Bending apparatus



Dec. 26, 1967 J. K. FAULL 3,359,776

BENDING APPARATUS Filed Jan. 4, 1965 4 Sheets-Sheet l INVENTOR. \JAMES: KFAULL A WEE/V136 Dec. 26, 1967 J. K. FAULL 3,359,776

BENDING APPARATUS Filed Jan. 4, 1965 4 Sheets-Sheet 2 INVENTOR LJAME$ K FAULL BYW/MW M/fg A TTOR/VL' ya Dec. 26, 1967 J. K. FAULL 3,359,776

I SENDING APPARATUS Filed Jan. 4, 1965 4 Sheets-Sheet 3 X Ptg l.

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ml 1 INVENTOR. dAMEs K. FAULL.

Dec. 26, 1967 J, K. FAULL 3,359,776

SENDING APPARATUS Filed Jan. 4, 1965 4 Sheets-Sheet '1.

\Q/l I /1 i INVENTOR. \JAMEfi K. FAULL /ham M/QM A TTORNE )15 United States Patent 3,359,776 BENDING APPARATUS James K. Faull, 16 Walker Court, Poland, Ohio 44514 Filed 'Jan. 4, 1965, Ser. No. 423,143 13 Claims. (Cl. 72-389) ABSTRACT OF THE DISCLOSURE Tube bending apparatus in which the tube to be bent is gripped between a bending head and a pair of bending arms normally disposed in end-to-end abutting relat1on. The bending arms are respectively pivoted about axes spaced apart an amount equal to twice the radius to which the tube is to be bent and the spacing between the arm pivots is adjustable to accommodate various bend radii while maintaining the normal, end-to-end abutting relationship of the bending arms.

The present invention relates to bending apparatus, more particularly to tube bending apparatus, and the principal object of the invention is to provide new and improved apparatus of the character described.

While apparatus for production bending of tubing has been available heretofore, such apparatus, even though it functioned properly, has been less than completely satisfactory since it has been expensive due to its complexity and quite limited in its ability to bend tubing of various diameters to various bend radii. In many cases, a change of tubing diameter and/ or change of bend radius required either separate apparatus or the time-consuming replacement of expensive parts in the basic apparatus.

In contrast, the present invention provides highly efficient bending apparatus which can readily bend various sizes of tubing to various bend radii by means of simple adjustments and by substitution of simple, low-cost parts. These and other advantages will readily become apparent from a study of the following description and from the drawings appended hereto.

In the drawings accompanying this specification and forming a part of this application there is shown for purpose of illustration, an embodiment which the inwantion may assume, and in these drawings:

FIGURE 1 is a broken, side elevational view of a preferred embodiment of the invention, parts on the near side being broken away to illustrate the underlying structure,

FIGURE 2 is a broken, sectional view generally corresponding to the line.2-2 of FIGURE 1.

FIGURE 3 is an exploded perspective view of certain details,-

FIGURE 4 is a view similar to FIGURE 1 but showing the present device during a stageof a bending operation,

FIGURE 5 is a view similar to FIGURE 4 but showing the device during another state of a bending operation,

FIGURE 6 is a view similar to FIGURE 1 but showing the device as adjusted to bend to a larger radius, and

FIGURE 7 is a perspective view of a detail seen in FIGURE 3 but proportioned to accommodate a larger diameter tube to be bent.

With reference first to FIGURES 1 and 2, the present device comprises a base plate 10 which is adapted to be secured by any suitable means to the bed of a conventional'press (not shown) and a bending head 11 adapted to be secured to the ram of such press for rectilinear movement along the axis or path of travel X toward and away from the base plate 10.

Removably'secured to thebase plate 10 in upstanding relation on opposite sides of the path of travel of the head 11 are bifurcated stands 12, each having spaced side 3,359,776 Patented Dec. 26, 1967 ice walls 13, 14 joined together by a lower, transverse wall 15 which terminates short of the adjoining ends of the stands 12 to provide operating clearance for means to be disclosed. The upper portions of the side walls 13, 14 of the stands 12, see also FIGURE 3, provide aligned apertures for receiving stubs shafts 16 which pivotally secure cradles 17 to respective stands 12 between their side walls.

Mounted in each cradle 17 is a tube nest 18 each having an upwardly directed longitudinally extending rectilinear groove 19 for closely receiving the tube to be bent.

I Adjoining ends of the tube nests 18 have depending,

rounded portions 20 for a purpose to appear. As best seen in FIGURES 2 and 3, the means presently provided for securing each tube nest to its cradle comprises flat, apertured clamp members 21 secured to respective cradles by screws 22 and having bevelled, overhanging end portions seated in respective, longitudinally extending rabbets 23 formed in opposite, upper sides of each tube nest. Means are provided for accurately locating each tube nest 18 within its cradle and with respect to the path of travel of the head 11, and as shown in FIGURE 1, a dog point set screw 23 is threaded into the floor of each cradle and projects upwardly thereof for closely fitting within any one of a series of depressions 24 formed in the underside of each tube nest 18.

Means are also provided for accurately and predeterminedly locating each stand 12 with respect to the path of travel of the bending head 11 and as best seen in FIG- URES 1 and 3, the upper surface of the base plate 10 and the lower surfaces of the stands 12 have cooperable serrations 25, 26 respectively, formed therein. Capscrews 27 project upwardly through the base plate 10 and are threaded into the stands 12 to secure the latter to the base plate, such screws passing through elongated slots 28 in the baseplate to provide the adjustment aforesaid of the stands.

Threaded into the base plate 10 and projecting downwardly therefrom is a threaded stud 29 encircled by a helical compression spring 30. The lower end of spring 30 is seated against a washer 31 which is slidable along the stud 29 and a nut 32 is threaded on the stud and provides an adjustable abutment for the washer 31 for a purpose to be seen. The upper end of spring 30 bears against a disk 33 which is slidable along the stud 29 and, projecting upwardly of the disk and slidably extending through the plate 10, are guide pins 34 to whose upper ends is secured a pressure pad 35. In the position of parts seen in FIGURE 1, spring 30 yieldably maintains the disk 33 against the underside of base plate 10 to maintain the pressure pad 35 as shown wherein the tube nests 18 are supported with their grooves 19 in aligned relation. Nut 32, of course, provides for adjustment of the spring pressure thus supporting the tube nests against rotation about their respective pivots.

With the parts positioned as seen in FIGURES 1 and 2, and noting that bending head 11 has an arcuate groove 36 aligned with the tube nest grooves 19 and also proportioned to closely receive the tube to be bent, such tube will be positioned within the tube nest grooves 19. It should be noted at this time. that the arcuate bending head has been chosen to provide the desired bend radius and that both the head and the tube nests have been chosen to provide the proper grooves required for the diameter of the tube being bent.

The stands 12 are shown positioned in opposed relation, each with its cradle pivot axis spaced from the axis of travel X of the bending head an amount equal to the radius to which the tube is to be bent. The tube nests 18 are shown adjusted on their cradles 17 so that they abut at the aforesaid axis of travel X of the head. It should be mentioned that in FIGURES 1 and 2, the apparatus is shown arranged to bend a relatively small diameter tube to the smallest radius of bend within the range of the illustrated apparatus.

With the tube T (FIGURE 4) resting upon the tube nests 18 as previously described, the press ram (not shown) on which the bending head 11 is mounted will be activated to move such head downwardly. As the bending head reaches the position seen in FIGURE 4, its downward movement will tend tobe arrested by the spring 30 holding up on the pressure pad 35. The ram, however, will have sufiicient power to overcome the resistance of spring 30' and thus will move the parts to the position seen in FIGURE wherein the tube T has been bent'approximately 90 degrees. In the event a lesser degree of bend is required, downward movement of the bending head will be arrested before the FIGURE 5 position is reached. Note that tilting movement of the tube nests 18 from the positions seen in FIGURE 4 to the positions seen in FIGURE 5 will be resisted by spring 30 whose exerted force for proper bending will be adjusted by the nut 32.

Following bending of the tube 7 as above-described, the bending head 11 will be elevated to the position seen in FIGURE 1, spring 30 will return tube nests 18 and all the associated parts to the position seen therein, and the now bent tube will be removed and replaced by the next tube to be bent.

In the event a larger diameter tube is to be bent to the same radius as thus far disclosed, the tube nests 18 will each be removed from their cradles 17 and replaced by tube nests 118 (FIGURE 7) each having an appropriately sized larger groove 119 for closely receiving the larger diameter tube to be bent. Also, the bending head 11 will be replaced by one having an arcuate groove corresponding to groove 36- (FIGURE 2) but large enough to closely receive such larger diameter tube.

When a tube of the size shown in FIGURES 4 and 5 is to be bent to a larger radius, for example, the largest radius of bend within the range of the illustrated apparatus, the bending head 11 will be replaced with a bending head 211 having the desired larger bend radius. The stands 12 will be moved away from each other so that the cradle pivot axis of each is spaced from the axis of travel X of the head an amount equal to the desired bend radius. The tube nests 18 will need not be replaced so long as there is no change of tube size but they will be adjusted in their cradles so that their adjoining ends abut as shown on the aforesaid axis of travel X of the head.

Obviously, in the event a bend radius intermediate those shown in FIGURES 1 and 6 is required, the appropriately sized bending head will be employed along with an appropriate adjustment of the stands 12 and the tube nests 18.

It is to be noted that the size of the serrations 25 of the base plate 10 is preferably such that the stands 12 will latch into place at more or less standard bend radii positions. For example, as herein shown, the spaces between adjoining serrations may be inch so that bend radii may be established at every /8 inch within the range of adjustment. Similarly, since with every adjustment of the stands 12 along the base there must be a corresponding but opposite adjustment of the tube nests 18 within their cradles 17, adjoining screw-receiving depressions 24- in the tube nests will likewise be spaced the same as the serrations 25 or, in the present instance, inch apart. As will be apparent, the provision of precise detent positions to which the stands and the tube nests may be positioned greatly facilitates adjustment of the apparatus to bend tubing to various radii and insures satisfactory operation and accurate, predictable results.

While the presently disclosed apparatus is shown and described as being designed to bend round in cross-section tubing, it will be apparent that tubing of other cross-sectional shapes may be bent by providing appropriately shaped grooves in the tube nests and the bending head.

4 Moreover, the apparatus can also be used to bend elongated stock other than tubing; for example, bar stock of various cross-sectional shapes. Accordingly, the use of the word tubing in the present specification and the claims is to be considered as an example rather than as a limitation.

In view of the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim:

1. Tube bending apparatus comprising a base, a pair of pivot stands shiftably secured to said base in spacedapart relation, a pair of bending arms normally disposed in end-to-end abutting relation for receiving the tube to be bent, a pivot carried by each of said stands and mounting respective arms aforesaid thereon, said pivots being spaced apart an amount equal to twice the radius to which the tube is to be bent, an arcuate bending head mounted for movement transversely of and toward said arms and along a path substantially bisecting the arm pivots to grip the tube between said head and said arms, means urging said arms about their pivots to end-to-end relation aforesaid and yieldably opposing movement of said arms about their pivots from such relation, and interengageable means in part carried by said base and in part carried by said stands providing for disposition of said stands at various preselected positions relative to the path of movement of said head to provide for bending of the tube to various preselected bend radii.

2. The construction of claim 1 wherein said stands each pivotally support a cradle, wherein said arms are secured to respective cradles, and wherein inter-engageable means are in part carried by respective cradles and in part carried by respective arms to provide for disposition of said arms relative to said cradles at various preselected positions correlated with the radius to which the tube is being bent.

3. The construction of claim 2 wherein identical spacing between adjoining, preselected positions is provided by said first-mentioned and said second-mentioned interengageable means.

4. Tube bending apparatus comprising a pair of bending arms normally disposed in predetermined, end-to-end relation for receiving a tube to be bent,

pivots for respective arms spaced-apart an amount equal to twice the radius to which the tube is to be bent,

an arcuate bending head mounted for movement transversely of and toward said arms and along a path bisecting said arm pivots to grip the tube between said head and said arms,

and means urging said arms about their pivots to endto-end relation aforesaid and yieldably opposing movement of said arms about their pivots from such relation.

5. The construction of claim 4 wherein said arm pivots are adjustable toward and away from the path of movement of said head to accommodate variations in the bend radius,

and wherein said arms are adjustable relative to and independently of respective arm pivots to maintain the predetermined, end-to-end arm relation aforesaid to properly support the tube during bending thereof.

6. The construction of claim 5 wherein said bending arms are in abutment in their normal relation aforesaid.

7. Tube bending apparatus comprising a pair of bending arms normally disposed in predetermined, end-t-o-end relation for receiving a tube to be bent,

pivots for repsective arms and spaced-apart from each other,

an arcuate bending head mounted for movement transversely of and toward said arms and along a path bisecting said arm pivots to grip the tube between said head and said arms,

and means urging said arms about their pivots to endto-end relation aforesaid and yieldably opposing movement of said arms about their pivots from such relation,

said arm pivots being adjustable toward and away from the path of movement of said head to accommodate variations in the bend radius,

and said arms being adjustable relative to and independently of respective arm pivots to maintain the predetremined, end-to-end arm relation aforesaid to properly support the tube during bending thereof.

8. Tube bending apparatus comprising a base,

a pair of pivot stands secured to said base in spacedapart relation,

a pair of bending arms pivotally carried by respective stands, said arms normally being disposed in endto-end relation for receiving the tube to be bent and said arms each having a groove for closely receiving such tube,

an arcuate bending head mounted for movement transversely of and toward said arms and along a path substantially bisecting the arm pivots to grip the tube between said head and said arms and said head having an arcuate groove for closely receiving the bent tube,

means urging said arms about their pivots to end-toend relation aforesaid and yieldably opposing movement of said arms about their pivots from such relation,

first interengageable means in part carried by said base and in part carried by said stands providing for disposition of the latter at various preselceted positions relative to the pah of movement of said head to provide for bending of the tube to various preselected radii,

and second interengageable means in part carried by respective arms to provide for disposition of the latter relative to said stands at various preseleced positions correlated with the radius to which the tube is being bent.

9. The construction of claim 8 wherein said pivot stands are so disposed that respective pivots carried thereby are spaced from each other an amount equal to twice the radius to which the tube is to be bent,

and wherein said bending arms are so disposed in their normal positions that their adjoining ends are in abutting relatioin.

10. The construction of claim 8 wherein identical spacing between adjoining, preselected positions is provided by said first and said second interengageable means.

11. The construction of claim 10 wherein said means urging said arms about their pivots comprises a member engaged with those arm ends adjacent each other, wherein a spring urges said member to arm engagement, and wherein means are provided to adjust the effective force of said spring to vary arm movement resistance aforesaid.

12. The construction of claim 11 wherein said member has sliding connection with said base and sliding engagement with those arm ends adjacent each other.

13. The construction of claim 12 wherein a threaded rod is secured to said base, wherein said stands, arms, head and member are disposed on one side of said base and said rod is disposed on the other side thereof, wherein said spring is a helical compression spring and encircles said rod, wherein one end of said spring bears against a collar adjacent said base on said other side thereof and which likewise encircles said rod, wherein guide pins slida-bly extend through said base and connect said collar to said member for unitary movement, and wherein nut means is threaded on said rod and provides an adjustable abutment for the other end of said spring so that compression on the latter can be varied thus varying the force which resists movement of said arms away from their end-to-end relation aforesaid.

10/ 1952 Great Britain. 1/ 1962 Great Britain.

RICHARD J. HERBST, Primary Examiner. E. M. OOMBS, Assistant Examiner. 

1. TUBE BENDING APPARATUS COMNPRISING A BASE, A PAIR OF PIVOT STANDS SHIFTABLY SECURED TO SAID BASE IN SPACEDAPART RELATION, A PAIR OF BENDING ARMS NORMALLY DISPOSED IN END-TO-END ABUTTING RELATION FOR RECEIVING THE TUBE TO BE BENT, A PIVOT CARRIED BY EACH OF SAID STANDS AND MOUNTING RESPECTIVE ARMS AFORESAID THEREON, SAID PIVOTS BEING SPACED APART AN AMOUNT EQUAL TO TWICE THE RADIUS TO WHICH THE TUBE IS TO BE BENT, AN ARCUATE BENDING HEAD MOUNTED FOR MOVEMENT TRANSVERSELY OF AND TOWARD SAID ARMS AND ALONG A PATH SUBSTANTIALLY BISECTING THE ARM PIVOTS TO GRIP THE TUBE BETWEEN SAID HEAD AND SAID ARM, MEANS URGING SAID ARMS ABOUT THEIR PIVOTS TO END-TO-END RELATION AFORESAID AND YIELDABLY OPPOSING MOVEMENT OF SAID ARMS ABOUT THEIR PIVOTS FROM SUCH RELATION, AND INTERENGAGEABLE MEANS IN PART CARRIED BY BASE AND IN PART CARRIED BY SAID STANDS PROVIDING FOR DISPOSITION OF SAID STANDS AT 